Patchwork [(5/7)] Widening multiplies for mis-matched mode inputs

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Submitter Andrew Stubbs
Date Aug. 19, 2011, 2:42 p.m.
Message ID <4E4E7672.5040708@codesourcery.com>
Download mbox | patch
Permalink /patch/110682/
State New
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Comments

Andrew Stubbs - Aug. 19, 2011, 2:42 p.m.
On 14/07/11 15:31, Richard Guenther wrote:
> Ok.

I've just committed this patch with no real changes. I've just updated 
the testcase.

Andrew

Patch

2011-08-19  Andrew Stubbs  <ams@codesourcery.com>

	gcc/
	* tree-ssa-math-opts.c (is_widening_mult_p): Remove FIXME.
	Ensure the the larger type is the first operand.

	gcc/testsuite/
	* gcc.target/arm/wmul-7.c: New file.

--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/wmul-7.c
@@ -0,0 +1,11 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-require-effective-target arm_dsp } */
+
+unsigned long long
+foo (unsigned long long a, unsigned char *b, unsigned short *c)
+{
+  return a + *b * *c;
+}
+
+/* { dg-final { scan-assembler "umlal" } } */
--- a/gcc/tree-ssa-math-opts.c
+++ b/gcc/tree-ssa-math-opts.c
@@ -2054,9 +2054,17 @@  is_widening_mult_p (gimple stmt,
       *type2_out = *type1_out;
     }
 
-  /* FIXME: remove this restriction.  */
-  if (TYPE_PRECISION (*type1_out) != TYPE_PRECISION (*type2_out))
-    return false;
+  /* Ensure that the larger of the two operands comes first. */
+  if (TYPE_PRECISION (*type1_out) < TYPE_PRECISION (*type2_out))
+    {
+      tree tmp;
+      tmp = *type1_out;
+      *type1_out = *type2_out;
+      *type2_out = tmp;
+      tmp = *rhs1_out;
+      *rhs1_out = *rhs2_out;
+      *rhs2_out = tmp;
+    }
 
   return true;
 }